I voted "other" because last winter I had a car pass and some snow flew by my face, luckily missing. I assumed that one of the kids in the backseat threw it so I raced after them and got the plate # and then pulled over and got out my cell phone. But thinking about it I realized I couldn't swear the snow didn't just slide off the car as it passed. So I just wrote it off as good practice for next time. Fortunately, there has been no next time.